Leukaemia success heralds wave of gene-editing therapies

Pioneering gene-editing technology has saved the life of a one year old girl with acute lymphoblastic leukaemia.

All conventional therapy had failed ( chemotherapy and bone marrow transplant), so doctors decided to try genetically engineered immune cells from a donor. The idea of the gene therapy is to extract immune cells called T-cells from a healthy donor, and expose them to a type of DNA-cutting enzyme called a TALEN. The enzyme deactivates immune genes that would otherwise cause the donor cells to attack when injected into a person with leukaemia, and modifies genes to protect the new cells from anti-cancer drugs that the patient is taking. The individual then undergoes therapy to destroy his or her own immune system and cancer cells, which is replaced with the modified cells. The treatment is not a permanent solution for leukaemia patients but rather a ’bridge‘ to keep the person alive until a matched T cell donor can be found. Little Kayla responded well to the treatment and had a repeat bone marrow transplant.